Abrogation of heat-shock protein (HSP)70 expression induced cell growth inhibition and apoptosis in human androgen-independent prostate cancer cell line PC-3m

摘要

Aim: To investigate the effect of abrogating heat shock protein (HSP) 70 expression by antisense HSP70 oligonucleotides treatment on human androgen-independent prostate cancer cell line PC-3m growth. Methods: PC3m cells were treated with 0-16μmol/L antisense HSP70 oligomers for 0-100 hr. Cell growth inhibition was analyzed using a trypan blue dye exclusion test. Apoptotic cells were detected and confirmed by flow cytometric analysis and DNA fragmentation analysis. The protein expression of HSP70 and bcl-2 affected by antisense HSP70 oligomers were determined using Western blot. Results: Antisense HSP70 oligomer induced apoptosis and then inhibited proliferation of PC-3m cells in a dose- and time-dependent manner. Ladder-like patterns of DNA fragments were observed in PC-3m cells treated with 10μmol/L antisense HSP70 oligomer for 48 hr or 8μtmol/L for 72 hr on agarose gel electrophoresis. Antisense HSP70 oligomer pretreatment enhanced the subsequent induction of apoptosis by heat shock in PC-3m cells. In addition, undetectable HSP70 expression was observed at a concentration of 10μtmol/L antisense HSP70 oligomer treatment for 48 hr or 8μtmol/L for 72 hr in Western blot, which was paralleled by decreased expression levels of anti-apoptotic protein bcl-2. Conclusion: HSP70 antisense oligomer treatment abro-gates the expression of HSP70, which may disrupt HSP70-bcl-2-interactions and further down-regulate bcl-2 expression,in turn inducing apoptosis and inhibiting cell growth in PC-3m cells. (Asian JAndro12004 Dec;6:319-324)